EP1227303A2 - Ultrasound flow meter with interchangeable measurement section - Google Patents

Abstract

Flowmeter has a connection armature (2), inlet (4) and outlet (5) with an ultrasonic measurement capsule (3) mounted on the connection armature with the housing (9) of the capsule containing a measurement path with inlet (6) and outlet (7). The flow direction is changed in the region of the connection armature with the connection armature having an open connection region on which the measurement capsule is mounted.

Description

The present invention relates to a flow meter for fluid media a connection fitting, an inlet, an outlet, one at the Connection fitting mountable or demountable measuring capsule with housing, Ultrasonic measuring section, at least one with the measuring section and the inlet of the Connection fitting related inflow channel and at least one in connection with the measuring section and the outlet of the connection fitting standing outflow channel.

Such a flow meter is already known from EP 1 020 711 A1. The Connection fitting of this flow meter is both on its top and trained open at the bottom, d. H. has a two-sided open Connection area into which a pre-assembled measuring capsule can be inserted. The The measuring section lies somewhat in the middle and at an angle of 90 ° to the longitudinal axis of the connections the connection fitting or the related pipeline. The The inlet channel of the measuring capsule has a smaller flow cross section than that related outlet of the connection fitting. Beyond that the flow within the measuring capsule up to the inlet of the measuring section redirected several times. In addition, there is a connection between the connection fitting and measuring capsule over a conical geometry and is therefore constructive consuming. This construction has the disadvantage that a free space in Masonry for the part of the tower projecting beyond the underside of the connection fitting Measuring capsule must be provided. This leads to increased costs. Furthermore there is a risk when replacing the measuring capsule that masonry parts over the rear opening in the intermediate area between the connection fitting and Measuring capsule can get and the function of the flow meter sustainable adversely affect.

The object of the present invention is the generic Flow meter to improve that its construction and Assembly including masonry work becomes easier and at the same time contamination by masonry and the like during a Exchange of the measuring capsule can be avoided.

This task is solved in the generic flow meter in that the flow is already deflected in the area of the connection fitting and the connection fitting has a connection area open on one side which the measuring capsule can be mounted. This will only make one Connection area created between connection fitting and measuring capsule, so that no additional wall recesses are necessary in the rear area.

The measuring capsule is expediently sandwiched onto the connection fitting placed. On the one hand, this facilitates assembly and disassembly, on the other hand this creates the possibility that already exists in existing installed connection fittings located mechanical counter against Easy to replace measuring capsules with an ultrasonic measuring section. Flow meters based on the ultrasonic measuring principle are subject to a lower one Wear, d. H. have a long service life and therefore make it possible to achieve longer authentication intervals.

According to one embodiment of the present invention, the measuring section is in the Measuring capsule essentially parallel to the course of the connection fitting connected pipeline or the related Connection elements of the connection fitting arranged. This will create a low height of the measuring capsule guaranteed.

Unless the construction height is so important, alternatives can be used Embodiments of the flow meter according to the invention also with an oblique or even perpendicular to the course of the connection fitting or with the Connection fitting connected pipeline may be arranged.

According to the invention, both the inflow channel and the outflow channel are the measuring capsule is provided in the area of the connection area open on one side. Here, the inflow channel and outflow channel can be parallel, in particular be arranged concentrically to each other. For example, the outflow channel provided within an annular inflow channel. This enables it at Need a central heat sensor in the inflow channel, d. H. immediately before the Measuring section or centrally in the outflow channel, d. H. immediately after the Position measuring section, which enables a very precise heat quantity detection is made possible. At the same time, the accuracy of the detection of the Difference in transit time within the measuring section is not affected.

The present invention further relates to a flow meter for fluids Media with a connection fitting, an inlet, an outlet, one at the Connection fitting mountable or demountable measuring capsule with housing, Ultrasonic measuring section, at least one with the measuring section and the inlet of the Connection fitting related inflow channel and at least one in connection with the measuring section and the outlet of the connection fitting standing outflow channel together with the inflow channel of the measuring capsule form a common flow channel with the inlet of the connection fitting, the - seen in the vertical section of the measuring capsule and connection fitting - in essentially without deflections or at least deflections smaller than 90 ° to The inlet of the measuring section leads and / or the inflow channel (6) of the measuring capsule (3) together with the inlet (4) of the connection fitting (2) a flow channel forms, which - seen in vertical section - essentially without deflections or at least deflections of less than 90 ° leads to the inlet of the measuring section and / or the outflow channel (7) together with the outlet (5) Flow channel forms, which - seen in vertical section - essentially without Deflections or at least deflections less than 90 ° from the outlet of the Measuring section leads to the deflection in the outlet (5).

This can result in measurement disadvantages due to undefined Pressure conditions due to deflections and the like avoided become, d. H. the accuracy of the measurement can be increased.

Another aspect of the invention is the special dimensioning of the Flow cross sections insofar as the flow cross section of the inlet of the Connection fitting less than or equal to the flow cross section of the Inflow channel of the measuring capsule and / or the flow cross section of the Outflow channel of the measuring capsule is less than or equal to the flow cross section of the Inlet of the connection fitting should be. This can Flow differences and inlet turbulence can be adjusted. About that in addition there are stalls, cross flows and oscillating Currents avoided.

According to an alternative embodiment of the invention, in the inflow range of Connection fitting to measuring capsule z. B. at the junction of Connection fitting with the measuring capsule an enlargement, in particular abrupt enlargement of the flow cross-section provided, whereby a strong reduction in flow velocity is generated. This enables the fluid medium with a stronger flow deflection in the To direct the inflow channel of the measuring section without a disproportionate increase of pressure loss. The differences in the inflow profile are in this case generated by the sudden enlargement of the flow cross section.

The inflow channel of the measuring capsule expediently takes the geometry and / or the course of the inlet of the connection fitting. Alternatively or in addition to this, this can also apply to the outflow channel.

In this way, an optimized flow guidance within the Measuring distance reached; which on the one hand has a low flow resistance high volume flows, on the other hand, the achievable Sound propagation time difference between a sound beam with and against the flow is as large as possible, but the necessary housing dimensions are not exceeded, d. H. enables a compact design of the measuring capsule becomes.

The diameter of the housing of the measuring capsule is expediently possibly apart from the brackets for the converter, smaller or at least the same, but not larger than the diameter with the Measuring capsule in connection fitting.

The design also enables sieve or flow straighteners in the Provide area of the inflow channel, which strong, installation-related Flow differences and inlet turbulence easily compensated can be. This applies to all (also secondary) aspects of Invention. The screen can also have slanted slats, which the Imprint an impulse, which in the direction of the inlet of the Ultrasonic measuring section has.

Another useful addition to the present invention is that a heat sensor for heat quantity measurement is provided, namely in Area of the connection fitting or the measuring capsule. Because of the special Construction of the flow meter according to the invention results in a much more freely accessible compared to the mechanical principle based measuring capsules. It is now possible to use the heat sensor either directly in the inflow channel or in the outflow channel of the measuring capsule, preferably positioned substantially centrally in the flow, whereby a particularly exact measurement of the heat quantity or heat loss becomes feasible. In the latter case, the heat sensor is either in the Entry or exit area, d. H. is optimally positioned.

Alternatively, there is also the option of using the heat sensor to position within the measuring section and in such a way that the sound at Heat sensor is bypassed, for example bypassed this laterally becomes.

Alternatively, the heat sensor can also be located in the area of the sound path be positioned, but then with a diameter that is less than or equal to of four times the wavelength, since there is none due to the heat sensor considerable sound losses or sound reflections occur.

The heat sensor can be in the housing of the measuring capsule - detached from the electronics (which may be legally protected, i.e. sealed) - positioned become. For example, the sensor can be locked laterally in a Electronics part lying housing may be arranged. The assembly site of the The heat sensor can be selected almost anywhere in the area of the measuring capsule become. For example, the holder of the heat sensor can be parallel or in acute angle to the longitudinal axis of the measuring capsule, d. H. from above into the measuring capsule be positioned running into it. Alternatively, the bracket of the Heat sensor also tangential to the measuring capsule, d. H. tangentially into the measuring capsule be arranged running into it.

The measuring section of the flow meter according to the invention can preferably be straight. Here, the sound from one end to the other end of the measuring path move linearly or to extend the Sound path reflected at least once within the linear measuring path become.

Alternatively, the measuring section can be, for example, by reflection or Deflection of the sound can also be provided as a curved measuring section.

A special case of the curved measuring section is the so-called vortex chamber represents which in an embodiment of the flow meter according to the invention is used.

A special configuration of the swirl chamber comprises an annular space or Circular space in which the ultrasonic wave moves along the annulus. The Annulus has an overflow in a centrally arranged outflow channel.

The inlet channel is separated from the outlet channel in the straight one Ultrasonic measuring section over a parting plane, which is preferably oblique, straight or can be curved. This inclined plane also ensures that the water reach the outlet of the measuring section via the outflow channel can.

The inflow channel is advantageously ring-shaped educated.

Fig. 1

eine perspektivische Ansicht einer Ausgestaltung des erfindungsgemäßen Durchflußmessers mit an der Oberseite installiertem Wärmefühlereinsatz sowie mit linearer Meßstrecke;

Fig. 2

eine Schnittdarstellung der Anordnung gemäß Fig. 1 in Längsrichtung zu den Anschlußelementen der Rohrleitung;

Fig. 3

eine Schnittdarstellung in Querrichtung zur Achse der Anschlußelemente der Rohrleitung;

Fig. 4

eine alternative Ausgestaltung des erfindungsgemäßen Durchflußmessers mit an der Oberseite der Meßkapsel mittig angebrachtem Wärmefühlereinsatz sowie einer Wirbelkammer als Meßstrecke;

Fig. 5

die Anordnung gemäß Fig. 4 in Draufsicht;

Fig. 6

die Anordnung gemäß den Figuren 4 und 5 im Längsschnitt entlang der Achse der Anschlußelemente bzw. Rohrleitung;

Fig. 7

die Darstellung eines Schnitts durch die Wirbelkammer der Anordnung gemäß den Figuren 4-6;

Fig. 8

eine alternative Ausgestaltung des erfindungsgemäßen Durchflußmessers mit seitlich tantential zur Meßkapsel angeordnet und Wärmefühlereinsatz sowie eine Wirbelkammer als Meßstrecke in Seitenansicht;

Fig. 9

eine Draufsicht auf die Ausgestaltung gemäß Fig. 8;

Fig. 10

einen Teilschnitt gemäß der Linie C - C von Fig. 9;

Fig. 11

einen Schnitt A - A gemäß der Darstellung nach Fig. 9 sowie

Fig. 12

eine Schnittdarstellung entsprechend der Ebene E - E in Fig. 8.

Several useful embodiments of the present invention are explained in more detail below with reference to the drawing figures. For the sake of clarity, recurring features are identified only once in all embodiments with identical reference numerals. Show it:

Fig. 1

a perspective view of an embodiment of the flow meter according to the invention with a heat sensor insert installed on the top and with a linear measuring section;

Fig. 2

a sectional view of the arrangement of Figure 1 in the longitudinal direction to the connecting elements of the pipeline.

Fig. 3

a sectional view in the transverse direction to the axis of the connecting elements of the pipeline;

Fig. 4

an alternative embodiment of the flow meter according to the invention with a heat sensor insert mounted centrally on the top of the measuring capsule and a swirl chamber as a measuring section;

Fig. 5

the arrangement of Figure 4 in plan view.

Fig. 6

the arrangement according to Figures 4 and 5 in longitudinal section along the axis of the connecting elements or pipeline;

Fig. 7

the representation of a section through the vortex chamber of the arrangement according to Figures 4-6;

Fig. 8

an alternative embodiment of the flow meter according to the invention arranged laterally tantential to the measuring capsule and heat sensor insert and a swirl chamber as a measuring section in side view;

Fig. 9

a plan view of the embodiment of FIG. 8;

Fig. 10

a partial section along the line C - C of Fig. 9;

Fig. 11

a section A - A as shown in FIG. 9 and

Fig. 12

8 shows a sectional illustration corresponding to the plane E-E in FIG. 8.

Reference number 1 in Fig. 1 denotes an expedient embodiment of the Flow meter according to the invention in its entirety. The flow meter comprises a connection fitting 2, the connection elements 19, 20 with a Pipeline (not shown) for example water pipeline is connectable. The connection fitting carries in a sandwich-like manner on its upper side Arrangement a measuring capsule 3 with opposite receptacles 24, 25 for Measuring functional parts (not shown), for example ultrasonic transducers. It is a straight ultrasonic measuring section.

The flow meter 1 shown in FIG. 1 also has a Heat sensor insert 21, the 9 in the area of the top of the housing Measuring capsule 3 via a holder 12 and a cable 22 are not shown in FIG. 1 heat sensor shown placed inside the measuring capsule 3.

It is pointed out that - if no heat measurement is desired or should be necessary - the heat sensor insert 21 can be omitted as well.

From Fig. 2 it follows that the housing 9 of the measuring capsule 3 immediately with the measuring capsule 3 adjacent area of the connection fitting 2 - except for the Recordings 24, 25 do not protrude laterally.

The recordings 24, 25 can be used as an alternative to that shown in FIGS. 1 and 2 Copy form also arranged within the housing 9 of the measuring capsule 3 be preferably such that they are the adjacent connection fitting not or at least not significantly protrude. This results in a very Easy to assemble and disassemble with the connection housing installed.

2 is a one-sided open at the top of the connection fitting 2 Connection area 10 is provided, with the open bottom of the measuring capsule 3rd communicated.

The measuring capsule 3 and connection fitting 2 are over corresponding interlocking ring projections connected together, preferably screwed. In addition, a seal is provided in this area.

Inside the measuring capsule 3 there is an ultrasonic measuring section 8, which in the Design of the flow meter according to FIG. 2 is straight. The Measuring capsule 3 comprises an insert 15 which forms the measuring section 8 and which together with the housing 9 of the measuring capsule 3 an inflow channel 6 in the form of an annulus. This inflow channel 6 is with an inlet of the Measuring section 8, z. B. as shown in Fig. 2 form a plurality of Inlet ports 26 in communication. At the opposite end of the Measuring section 8 is an outlet, z. B. in the form of a plurality of Outlet openings 32 of the one formed by an inclined plane 17, 'separated space 18 connected to a central outflow channel 7 communicated. The ultrasonic measuring section 8 is the flow area of the Measuring capsule in which the ultrasonic signal is carried.

The outflow channel 7 merges into an outlet 5 of the connection fitting 2 the water in the area of the outlet of the connection fitting 2 is diverted and the Water pipe is fed again.

The inlet 4 in the deflected part of the connection fitting 2 is also already annular or at least partially annular and passes over the Connection area 10 in its extension in the also annular trained inflow channel 6 of the measuring capsule 3 and without one significant change in direction of the inflow channel.

The cross section of the inflow channel 6 is expediently larger or the same the cross section of the inlet 4 formed, causing flow differences and inlet turbulence can be avoided.

In the area of the inlet 4 of the connection fitting 2 or in the area of the Inflow channel 6 of the measuring capsule 3 can with additional (in Figures 2 and 3) not shown functional elements such. B. Seven and / or Flow rectifiers Flow differences and inlet turbulence be balanced.

2 is located at the front end of the bracket 12 of the Heat sensor insert 21 of the heat sensor 23 in the central area of the central outflow channel 7. Reference number 22 denotes a cable. According to Fig. 1 is the heat sensor insert 21 to the top of the measuring capsule 3 slightly oblique installed continuously to - past the measuring section 8 - the heat sensor 23 to be placed centrally in the discharge channel 7.

The flow cross section of the outflow channel 7 corresponds approximately to that Flow cross section of the outlet 5 of the connection fitting 2 to undesirable Prevent pressure due to flow congestion in the drain area.

Furthermore, the flow cross section of the inflow channel 6 is larger than that Flow cross section of the measuring section 8.

As is clear from FIG. 3, the use of the measuring capsule 3 or whose housing the inflow and outflow area to and from the measuring section 8th such that one with respect to flow cross-section and course adapted overall channel without redirecting the liquid Entry into the measuring section 8 is formed comes.

4 shows a further embodiment of the invention Flow meter in which instead of a linear measuring section a curved one Measuring section in the form of a vortex chamber 14 is used. Here is 4 and 6 in particular that the measuring capsule 3 with its Housing 9, the outer dimensions of the connection housing 2 not or at least only slightly overlooked. Reference numerals 27 and 28 are transducers marked, cf. 5 and 7, which are at the top of the by Vortex chamber 14 formed measuring section 8 are. A redirection of the Ultrasonic signals starting from the vertical to the horizontal is by means of with reflectors 32 connected to transducer 27, 28 is achieved, the reflectors 32 ultrasonic signals from transducers within the Pass the vortex chamber to annular reflectors 31 so that the ultrasound signals sent by the one transducer via the reflectors 32, 31 through the measuring section 8 to the opposite transducer.

This construction using a measuring section 8 in the form of a Vortex chamber 14 enables an extension of the measuring section and thus one Accuracy of the runtime determination with small dimensions.

The heat sensor insert 21 can advantageously be located centrally in the region of the Outflow channel 7 to be positioned.

Here too - as with the aforementioned configuration of the flow meter linear measuring section 8 - an annular extension of the inlet 4 of the Connection fitting 2 given through the inflow channel 6 of the measuring capsule 3. How from 6, there is an additional sieve 29 in the area of the inflow channel 6 arranged extending over the entire circumference of the inflow channel 6.

In operation, water flows in a ring over the inlet 4 of the connection fitting 2 the inflow channel 6 of the measuring capsule 3 and passes through another in Area of the vortex chamber arranged annular extension 30 over circumferentially arranged, inclined inlet openings 26 into the interior of the Vortex chamber 14 and then flows over the overflow 16 and Outflow channel 7 via the outlet 5 of the connection fitting 2 centrally.

Because of the annular swirl chamber 14, there is the possibility of Heat sensor insert 21 from above, in particular through the middle of the housing 9 Position measuring capsule 3 centrally in outflow channel 7.

As an alternative to this, the heat sensor insert 21 can just as well - as shown in FIG 8-11 is shown in the area of the annular inflow channel 6 the measuring capsule 3 are positioned.

Here, the bracket 12 of the heat sensor insert 21 via a Side region of the housing 9 of the measuring capsule 3 is provided tangentially in introduced the inflow channel 6.

The heat sensor is located immediately in front of the in the case of Design according to Figures 8-11 annular vortex chamber. Otherwise corresponds to the design of the flow meter according to Figures 8-11 Construction of Figures 6 and 7.

The flow meter according to the invention enables use conventional connection fittings for mechanical meters and thus the Exchanging existing mechanical meters with measuring capsules physical measuring sections, in particular ultrasonic measuring sections. About that In addition, the flow meter can be easily and without due to its construction the risk of dirt getting inside the connection fitting or Reach the measuring chamber, be replaced. In addition, a sensor can due to the special construction without problems immediately before or after Measuring section or even be positioned within the measuring section. The Invention therefore makes a very special contribution to the relevant technical field.

Claims (13)

Flow meter for fluid media with a connection fitting (2), an inlet (4), an outlet (5), a measuring capsule (3) with housing (9), an ultrasonic measuring section (8) that can be mounted or removed on the connection fitting, at least one inflow channel (6) that is connected to the measuring section (8) and the inlet (4) of the connection arm (2) ) and at least one outflow channel (7) connected to the measuring section (8) and the outlet (5) of the connection fitting (2), characterized in that
the flow in the area of the connection fitting (2) is deflected and the connection fitting (2) has a connection area (10) which is open on one side and onto which the measuring capsule (8) can be mounted. Flow meter according to claim 1,
characterized in that
the measuring capsule (3) can be placed in a sandwich on the connection fitting (2). Flow meter according to claim 1 or 2,
characterized in that
Inflow channel (6) and outflow channel (7) are provided in the area of the one-sided open connection area (10). Flow meter according to one of the preceding claims,
characterized in that
the inflow channel (6) of the measuring capsule (3) together with the inlet (4) of the connection fitting (2) forms a flow channel which - seen in vertical section - leads essentially without deflections or at least deflections of less than 90 ° to the inlet of the measuring section and / or the outflow channel (7) together with the outlet (5) forms a flow channel which - seen in vertical section - leads essentially without deflections or at least deflections of less than 90 ° from the outlet of the measuring section to the deflection in the outlet (5). Flow meter according to one of the preceding claims,
characterized in that
the flow cross section of the inlet (4) of the connection fitting (2) is less than or equal to the flow cross section of the inflow channel (6) of the measuring capsule (3) and / or the flow cross section of the outflow channel (7) of the measuring capsule (3) is less than or equal to the flow cross section of the inlet (4) the connection fitting (2). Flow meter according to one of the preceding claims,
characterized in that
the inflow channel (6) of the measuring capsule (3) the geometry and / or the course of the inlet (4) of the connection fitting (2) and / or the outflow channel (7) of the measuring capsule (3) the geometry and / or the course of the outlet ( 5) of the connection fitting (2). Flow meter according to one of the preceding claims,
characterized in that
a heat sensor (23) is provided in the area of the connection fitting (2) or the measuring capsule (3), preferably in the inflow channel (6) or outflow channel (7), where it is preferably positioned essentially centrally in the flow. Flow meter according to claim 7,
characterized in that
the heat sensor (23) is arranged within the measuring section (8), in particular in such a way that the sound is conducted past the heat sensor (23), in particular laterally past it. Flow meter according to one of claims 7 or 8,
characterized in that
the heat sensor (23) has a holder (12) which is positioned parallel or at an acute angle to the longitudinal axis of the measuring capsule (3). Flow meter according to one of claims 7-9,
characterized in that
In addition to the heat sensor (23), a further external heat sensor is provided and the installation conditions in relation to the position within the flow are the same. Flow meter according to one of the preceding claims,
characterized in that
the measuring section (8) is straight or a curved measuring section (8), in particular in the form of a swirl chamber (14), is provided. Flow meter according to claim 11,
characterized in that
the swirl chamber (14) is formed by an annular space (15), which is connected either via an overflow (16) or via slots to an outflow channel (7), which is arranged in the middle, an inclined, straight or arched plane (17) It is provided which separates the inflow channel (6) from the outflow channel (7) and the measuring section (8) penetrates the inclined plane (17). Flow meter according to claim 12,
characterized in that
the outlet of the measuring section (8) is connected to the outflow channel (7) via a space (18) partially delimited by the inclined plane (17).

Images